Serum lipids can convert bovine myogenic satellite cells to adipocytes

Abstract

Serum lipid (SL) is a commercially available cholesterol-rich, proteinaceous compound extracted from bovine serum. Here we investigated the adipogenic transdifferentiation potential of SL on bovine myogenic satellite cells. Exposure of satellite cells to SL could generate lipid droplets on day 2, and further exposure to SL increased cytoplasmic lipid accumulation giving adipocyte morphology. The expression analysis of PPAR gamma and GPDH adipocyte markers along with Oil-red-O staining results confirmed the transdifferentiation potential of SL. When cells were treated at different concentrations (5, 10, 20, 40 μl/ml) of SL, the results indicated that even levels as low as 5 μl SL /ml could induce transdifferentiation, and maximum induction was obtained at 20 μl SL/ml. After treatment with SL at different concentrations the expression levels of PPAR gamma varied significantly (p<0.05), whereas the expression of other adipogenic transcription factors showed no difference, indicating that SL acts through PPAR gamma. The combined effect of SL and troglitazone proved to be the best combination for induction of transdifferentiation compared to the individual effect of SL or troglitazone. Thus, overall results clearly show that SL induces transdifferentiation of bovine myogenic satellite cells to adipocytes.